• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.251-261
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• 1987

This study was attempted to increase the production of L-Threonine by Brevibacterium Flavum ATCC 14067, To select the strain which produce the highest threonine, mutants ere induced by N-methyl-N'-nitro-N-nitrosoguanidine treatment. The composition of media and cultural condition for its overproduction of threonine were also studied. In a threonine producer, strain B-13(Met-) was the strain producing the highest amount of threonige among methionine, lysine and isoleucine auxotrophs. The following results were obtained. 1. The wild strain and B-13(Met-) produced threonine 1.4mg/ml and 4.86mg/ml , respectively. 2. The optimum composition of medium for producing threonine by Brevibacterium Flavum B-13 was glucose 10%, ammonium sulfate 4%, potassium phosphate monobasic 0.2%, magnesium sulfate 0.05%, biotin $200{\mu}l$, thiamine $300{\mu}l$. Addition of nicotinic acid also led to increase L-threonine production. 3. In addition of organic nutrients to the fermentation medium, peptone n'ere effective and addition of methionine $100{\mu}g/ml$ produced the highest amount of L-Threonine. Aspartic acid and homoserine were also effective when these amino acid were added to the fermentstion medium. 4. Cultural conditon on threonine production by B-16 were investigated. The optimum pH was 7.0-8.0. The highest amount of threnine was produced after 4 days of cultural period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.684-688
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• 2003

The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.15-21
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• 2017

In the present work, the synergistic effect of seaweed addition on organic acid production from sludge was investigated. The batch experiment was conducted at various mixing ratios of sewage sludge and seaweed (100:0, 75:25, 50:50, 25:75, 0:100 on a COD basis) under the substrate concentration of 20 g COD/L. The fermentation temperature was conducted under mesophilic condition ($35^{\circ}C$) and a heat-treated ($90^{\circ}C$ for 20 min) anaerobic digester sludge was used as a seeding source to suppress the methanogenic activity, The results showed that the amount of organic acid production increased as the content of seaweed increased: organic acids were 1.45, 3.22, 4.28, 5.24 and 4.82 g COD/L for the mixing ratio of 100:0, 75:25, 50:50, 25:75 and 0:100 respectively. The synergistic effect was calculated based on the organic acid production of individual sludge and seaweed, and was found to be 0.92, 1.14, 1.26 g COD/L at the mixing ratio of 75:25, 50:50 and 25:75, which indicates that 40% of synergy was obtained when 25% of seaweed was added. The synergistic effect could be ascribed to the high C/N ratio and biodegradability of seaweed.

• Microbiology and Biotechnology Letters
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• v.28 no.2
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• pp.80-86
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• 2000

To develop thermotolerant ethanol producing yeast strains, the protoplasts of Saccharomyces carlsbergensis having good fermentability at $30^{\circ}C$ and Kluyveromyces marxianus able to grow at $42^{\circ}C$ were fused. Under the optimal conditions for protoplast formation, the frequency of protoplast formation of S. carlsbergensis was 92 - 94% and that of K. marxianus was 98%. Fusion frequency between S. carlsbergensis and K. marxianus was $1.4\times10^{-6}-4.8$\times10^{-7}$. Among the 27 fusants obtained, 6 fusants were able to grow at $42^{\circ}C$. While the parental strains produced 3.2-3.4%(w/v) ethanol after 3 days from the fermentation medium containing glucose, fusants SK41-4 and SK53-22 produced 5.2%(w/v) ethanol in the same condition. The thermotolerance of SK53-22 was not high, but that of SK41-4 was quite high.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.54-61
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• 2007

The influences of pH were investigated for anaerobic hydrogen gas production under the constant pH condition ranged from pH 3 to 10. Carbon dioxide and hydrogen gas were main components of the gas but methane was not detected in the produced gas when sucrose was added in enrichment medium. When the modified Gompartz equation was applied for the statistical analysis of experimental data, a hydrogen production potential and maximum gas production rate at pH 5 were 1,182 mL and 112.46 mL/g dry wt biomass/hr. The hydrogen conversion ratio was 22.56%. The butyrate/acetate ratios at pH 5 and pH 6 are 1.63 and 0.38. Higher butyrate/acetate ratio produced more hydrogen gas generation. The Haldane equation model was used to find the optimum pH and fitted well with the experimental data$(r^2=0.98)$. The optimum pH and specific hydrogen production were 5.5 and 119.61 mL/g VSS/h.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.60-66
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• 1996

To investigate a possible application of three strains of lactic acid bacteria(strain No. 49. No. 61. No. 75) from kimchi in milk fermentation industry, the optimal condition for production of intracellular ${\beta}-galactosidase$ from Lactobacillus(L.) plantarum and its enzymatic properties were examined. The preferable carbon source of the medium for strain No. 49 in production of ${\beta}-galactosidase$ was MRS broth with 1.0% lactose instead of dextrose of pH 65. for strain No. 75 with 1.0% galactose and for strain No. 61 with 3.0% lactose at pH 7.5, respectively. The maximum enzyme production from strain No. 49, No. 75 was observed after 48 hours culture at $30^{\circ}C$ in a medium containing the appropriate carbon source, from strain No. 61 after 48 hours culture at room temperature. The optimum temperature for ${\beta}-galactosidase$ activity from L. plantarum was $60^{\circ}C$ for strain No. 49, $37^{\circ}C$ for strain No. 61 and $50^{\circ}C$ for strain No. 75, respectively. The heat stability of enzyme activities for all three strains remained 90% at $45^{\circ}C$. The optimal pH was pH 6.5 and enzyme activities were most stable at pH for all three bacteria.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.291-294
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• 2008

The Streptomyces padanus isolate TH04, isolated from mummified peaches, showed strong antifungal activity to Monilinia fructicola. The inhibition activity of the isolate TH04 to mycelial growth and spore germination at 1% concentration of sub-antifungal powder made from culture suspension (CS) was ranged from 79.8% to 81.0% and from 73.9% to 75.8% to M. fructicola four strains, respectively. In the test of antifungal activity in mixed culture of the isolate and M. fructicola, inhibition rate was 7.5%, 86.8% and 94.0% in 0.01, 0.1, and 1% concentration of CS containing bacterial cell of the isolate, respectively. On apples (cultivar; Fuji), the control values of the isolate TH04 crude filtrates (0.1 and 1%) were 85.9% and 100%, respectively. The results suggest that the isolate TH04 indicate development possibility as biocontrol agent of brown rot caused by M. fructicola with the study on delivery method and fermentation condition to produce an antifungal compound.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.656-663
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• 2013

This study using yogurt of food in order to increase the conservativeness and stability of lactobacillus, to be deliciously flavored and give it visual differential effect, were described regarding making the preparing method of double matrix capsulation in food industries. Our study group was especially made to soft and moisture cream using 5wt% of sucrose ester emulsifier as first capsulation. Double matrix capsulation was formed with the best stabilized bead type capsules when it blended 1:3 ratio of chitosan and alginate. The bead diameter size was about 2.5~4mm (mean diameter: 3mm). Activity of lactobacillus containing cream for depending on various pH variations showed that alkalinity ($pH=10.3{\pm}0.3$) condition was higher than acidity ($pH=4.3{\pm}0.3$) and neutrality ($pH=7.12{\pm}0.2$) conditions. After a month, it also was certified to the activity of lactobacillus in incubated at $37^{\circ}C$ in culture medium. As application of food industry, we developed the containing lactobacillus capsule and 5 colored kinds of double matrix capsulation in yogurt cream. As for above mentioned those results, one of tool to stabilize the living lactobacillus, doubled matrix capsulation greatly be expected to contribute to food industry. Furthermore, it can be expected to apply the drug delivery system (DDS) to active ingredients of stabilizing technologies at drug and cosmetic industries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.598-604
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• 2008

This study was carried out to develop a new traditional alcoholic beverage by using lily scale in order to utilize lily scale as a new matter for nutritious foods. The condition of alcohol fermentation was investigated by the addition of 2.5, 5.0, 7.5, 10.0, 12.5 and 15.0% dried lily scale and 10, 20, 30, 40 and 50% raw lily scale into mash, respectively. The maximum amount of ethanol was produced when 15% dried lily scale and 20% raw lily scale were added to cooked rice at $25^{\circ}C$ for 10 days. In overall acceptability of sensory evaluation, the LSD-5 alcoholic beverage (added 5% dried lily scale into mash) and LSR-20 alcoholic beverage (added 20% raw lily scale into mash) showed the best acceptability. Physiological functionalities of LSD-5 and LSR-20 alcoholic beverage were investigated. Electron donating ability by DPPH solution ($16.5{\sim}23.2%$), SOD-like activity ($20.4{\sim}24.7%$), ACE inhibitory activity ($24.7%{\sim}78.2%$) and tyrosinase inhibitory activity ($57.4{\sim}62.6%$) of LSD-5 and LSR-20 alcoholic beverage were better than the control (non-added liquor). Moreover, acceptability and physiological functionalities of LSD-5 alcoholic beverage are better than LSR-20.

• Journal of Life Science
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• v.27 no.6
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• pp.702-707
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• 2017

Insects and their extract have been traditionally used as medicinal resources in Asia. Recently, Gryllus bimaculatus and the larva of Tenebrio molitor, Protaetia brevitarsis, and Allomyrina dichotoma were enlisted as general food ingredients by Korean Ministry of Food and Drug Safety. As the interest in these insects is growing, the detailed investigation is needed for the standardization of suitable and safe rearing techniques. This survey was conducted via personal interviews about edible insect rearing farms in Korea. The basic feed is fermented oak sawdust for P. brevitarsis and A. dichotoma and wheat bran for T. molitor. The various feed additives are blended with each farm's own recipes. The overall growth condition, including sawdust fermentation method, feeding period, and rearing density, varies among the investigated farms. It seems that weight of last instar larva was correlated with the rearing density and duration of the larval period. The heavy metal contents were analyzed after 48 hour starvation and they were very small amount or not detected in investigated insects. We believe that the present data will contribute to develop and standardize the safe rearing techniques of edible insects in Korea.